US5500499A - Contacts material for vacuum valve - Google Patents

Contacts material for vacuum valve Download PDF

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Publication number
US5500499A
US5500499A US08/181,085 US18108594A US5500499A US 5500499 A US5500499 A US 5500499A US 18108594 A US18108594 A US 18108594A US 5500499 A US5500499 A US 5500499A
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United States
Prior art keywords
constituent
contacts
arc
proof
auxiliary
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Expired - Fee Related
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US08/181,085
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English (en)
Inventor
Tsuneyo Seki
Tsutomu Okutomi
Atsushi Yamamoto
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Toshiba Corp
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Toshiba Corp
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Assigned to KABUSHIKI KAISHA TOSHIBA reassignment KABUSHIKI KAISHA TOSHIBA ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: OKUTOMI, TSUTOMU, SEKI, TSUNEYO, YAMAMOTO, ATSUSHI
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00—Contacts
    • H01H1/02—Contacts characterised by the material thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00—Contacts
    • H01H1/02—Contacts characterised by the material thereof
    • H01H1/0203—Contacts characterised by the material thereof specially adapted for vacuum switches

Definitions

  • This invention relates to a contacts material for a vacuum valve of improved breaking performance.
  • contacts materials for vacuum valves include as important requirements low and stable rise in temperature and low and stable contacts resistance.
  • some of these requirements are mutually antagonistic, so it is difficult to satisfy all the requirements by a single metal.
  • contacts materials have therefore been developed by combining two or more elements so as to mutually complement the deficiencies of each others performance, and to meet specific applications such as large current use or high withstanding voltage use, and they have excellent characteristics in their own way.
  • performance in respect of increasingly severe requirements still leaves something to be desired.
  • the inventors carried out breaking tests on contacts materials manufactured by a sintering method or melting method using conductive constituents and arc-proof materials such as Ti, Zr, V, or Y having a larger getter action than Cr and a more appropriate vapor pressure and melting point than CF.
  • JEC4 test here JEC is the abbreviation for Japan Electrotechnical Committee Standard, of repeated contact closure and contact opening, better performance was obtained than with the conventional Cu--Cr contacts.
  • JEC5 test in which breaking is performed after passing current for a fixed time, good performance was not obtained, in that welding tended to occur. It would therefore be difficult to say that sufficient breaking performance is obtained with this concept, alone, and reliability was lacking.
  • one object of this invention is to provide contacts material for vacuum valve having excellent breaking performance.
  • the contacts material in which at least one of Ti, Zr, V, Y or Cr, which is capable of raising breaking capability to some degree, is used as arc-proof material, and, in order to maintain conductivity of the contacts material, the surface of the arc-proof material is covered with at least one auxiliary constituent consisting of Ta, Nb, W, or Mo.
  • a contacts material for a vacuum valve including an arc-proof constituent including at least one selected from the group consisting of chromium, titanium, zirconium, vanadium and yttrium, an auxiliary constituent including at least one selected from the group consisting of tantalum, niobium, tungsten and molybdenum and a conductive constituent including at least one selected from the group consisting of copper and silver.
  • an amount of the arc-proof constituent is from 10% to 70% by volume, a total amount of the arc-proof constituent together with the auxiliary constituent is not more than 75% by volume and an amount of the conductive constituent is the balance.
  • a contacts material for a vacuum valve including composite powders, each having an auxiliary constituent and an arc-proof constituent covered with the auxiliary constituent and a conductive constituent including at least one selected from the group consisting of copper and silver.
  • the arc-proof constituent includes at least one selected from the group consisting of chromium, titanium zirconium, vanadium and yttrium and the auxiliary constituent includes at least one selected from the group consisting of tantalum, niobium, tungsten and molybdenum.
  • Ti, Zr, V, Y and Cr have suitable melting point and vapor pressure and provide a getter action; they are therefore promising as arc-proof materials for raising the breaking capability.
  • arc-proof materials form solid solutions to an appreciable extent with the conductive constituent Cu or Ag, or form various intermetallic compounds. If therefore the conductive constituent and arc-proof constituent are simply melted, intermetallic compounds are formed between the arc-proof constituent and conductive constituent, with the result that the ⁇ -phase portion of the conductive constituent, which should provide the conductive constituent matrix of the contacts, is greatly reduced.
  • the conductivity of the contacts material tends to be lowered, since arc-proof constituent is melted in the ⁇ -phase of the conductive constituent to some degree. For these two reasons, sufficient conductivity of the contacts material cannot be obtained. Also, even if manufacture is carried out by a sintering method in which arc-proof constituent powder and conductive constituent powder are mixed, molded by pressuring and sintered, a phase of intermetallic compounds having the lower melting point than that of the conductive constituent is formed. So that sintering at the low temperature of for example 900 K must be employed, and sufficient hardness for use as a contacts material is not obtained, due to this low-temperature sintering. From this standpoint it is desirable to alloy the arc-proof constituent and auxiliary constituent to some degree.
  • FIG. 1 is a cross-sectional view of a vacuum valve to which a contacts material for the vacuum valve according to this invention is applied;
  • FIG. 2 is an enlarged cross-sectional view of the electrode portion of the vacuum valve shown in FIG. 1.
  • FIG. 1 is a cross-sectional view of a vacuum valve.
  • FIG. 2 is a view to a larger scale of the electrode portion of the vacuum valve shown in FIG. 1.
  • a circuit breaking chamber 1 is constituted by an insulating vessel 2 formed practically on a cylinder by insulating material and metal covers 4a, 4b provided at both ends thereof, with interposition of sealing fitments 3a and 3b, the chamber being maintained under vacuum.
  • Circuit breaking chamber 1 has arranged within it a pair of electrodes 7 and 8 mounted at facing ends of conductive rods 5 and 6.
  • upper electrode 7 is the fixed electrode
  • lower electrode 8 is the movable electrode.
  • a bellows 9 is fitted to conductive rod 6 of this electrode 8, so that movement in the axial direction of electrode 8 can be performed whilst maintaining vacuum-tightness within circuit breaking chamber 1.
  • a metal arc shield 10 is provided at the top of the bellows 9 to prevent bellows 9 being covered by arc vapor.
  • a metal arc shield 11 is provided in circuit breaking chamber 1 so as to cover electrodes 7 and 8, to prevent insulating vessel 2 being covered by arc vapor.
  • electrode 8 is fixed to conductive rod 6 by a brazing portion 12, or is press-fitted by caulking.
  • a contact 13a is mounted on electrode 8 by brazing a portion 14. Essentially the same construction is adopted for electrode 7.
  • Methods of manufacturing contacts material can be broadly classified into the infiltration method, wherein the conductive constituent is melted and allowed to flow into a skeleton formed of the arc-proof powder etc., and the sintering method, in which the powders are mixed in prescribed proportions and molded by pressuring and sintered.
  • a composite powder is employed that is obtained by covering arc-proof powder with the auxiliary constituent.
  • the method of covering may be by any method such as for example PVD or CVD, but, from the point of view of the vacuum components, PVD is preferable since the gas content can be reduced.
  • PVD and CVD are the abbreviations for Physical Vapor Deposit and Chemical Vapor Deposit, respectively.
  • the characterizing feature of this invention consists in manufacturing a skeleton by sintering this composite powder under for example vacuum atmosphere, and manufacturing contacts by infiltrating conductive constituent into this skeleton for example under vacuum atmosphere.
  • the feature is that a mixed powder of composite powder as described above and conductive powder blended in the prescribed amounts is molded by pressuring and then contacts are manufactured by sintering for example under vacuum. On observing the cross-sectional structure of the contacts that were thus manufactured, an alloy phase was observed between the arc-proof constituent and auxiliary constituent.
  • the Cu--Cr contacts used to provide the standard for the relative comparison of the circuit breaking test were manufactured by infiltrating Cu into a Cr skeleton (Comparative example 1).
  • 40 Ti--Cu contacts and 40 Ti--5W--Cu contacts were manufactured in a vacuum melting furnace (Comparative examples 2 and 3).
  • manufacture of contacts material was attempted by the sintering method by mixing Ti powder, W powder and Cu powder, followed by molding by pressuring and sintering.
  • the sintering temperature was above 750° C., the original shape of the molded body could not be maintained due to severe melting of Ti into Cu.
  • the sintering temperature was lower, the material strength could not be maintained. This trial manufacture of these contacts was therefore unsuccessful (Comparative example 4).
  • Cr powders having an average grain size of 100 micrometers were filled in a carbon crucible, and were sintered at a temperature of 1200° C. for one hour under a vacuum of 10 -3 Pa to obtain a skeleton.
  • An oxygen-free copper block was put on the skeleton and was melted at a temperature of 1150° C. for 0.5 hours under a vacuum of 10 -3 Pa. As a result, copper was infiltrated into the Cr skeleton to obtain a sample of a contacts material.
  • the mixed was molded by pressuring with a molding pressure of 8 metric tons per square centimeter to obtain a molded body. Then when the molded body was sintered at a temperature of 850° C. for one hour under a vacuum of a 10 -3 Pa, titanium was melted into copper severely, with the result that the original shape of the molded body could not be maintained.
  • Comparative examples 1 to 3 were of conductivity 30% IACS.
  • IACS is the abbreviation for International Annealed Copper Standard.
  • the circuit breaking capability of these contacts was taken as 1.0.
  • Ti--W--Cu contacts were manufactured by infiltrating Cu into a skeleton manufactured using a composite powder obtained by coating Ti powder with W, the Ti content being kept constant at 40 per cent.
  • the content of W which coated Ehe Ti powder was, variously, 2, 10, 30, and 40% (respectively, Examples 1, 2 and 3 and Comparative example 5).
  • Titanium powders having an average grain size of 100 micrometers were coated mechanically with tungsten powders having an average grain size of 3 micrometers to prepare composite powders.
  • the composition of the composite powder was approximately 5 vol % W--Ti by the analysis of the composite powder.
  • the composite powders were then filled in an aluminum oxide crucible and were sintered at a temperature of 1150° C. for one hour under a vacuum of 10 -3 Pa to obtain a skeleton.
  • An oxygen-free copper was infiltrated into the skeleton at a temperature of 1150° C. for 0.5 hours under a vacuum of 10 -3 Pa to obtain a sample of a contacts material.
  • Example 2 The same powders as in Example 1 were used, but the thickness of the coating of tungsten of the composite powder was made larger. As a result, the composite powders were obtained, whose composition was 10 vol % W--Ti according to the analysis of the composite powder. The following condition was the same as in Example 1 , and a sample of a contacts material was obtained.
  • Example 2 The same composite powders as in Example 2 were used, whose composition was 10 vol % W--Ti. Tungsten powders were further added to the composite powders so that the ratio of Ti:W was 4:3, and then were mixed. The mixed was then molded by pressuring with a molding pressure of 2 metric tons per square centimeter to obtain a molded body. The following sintering and infiltration conditions were the same as in Examples 1 and 2, and a sample of a contacts material was obtained.
  • Example 2 The same composite powders as in Example 2 were used, whose composition was 10 vol % W--Ti. Tungsten powders were further added to the composite powders so that the ratio of Ti:W was 4:4, and then were mixed. The mixed was then molded by pressuring with a molding pressure of 3 metric tons per square centimeter to obtain a molded body. The following sintering and infiltration conditions were the same as in Example 3, and a sample of a contacts material was obtained.
  • Vanadium powders having an average grain size of 100 micrometers were coated mechanically with tantalum powders having an average grain size of 3 micrometers to prepare composite powders.
  • the composite powders and copper powders having an average grain size of 40 micrometers were mixed in the volume ratio of 1:9.
  • the mixed was molded by pressuring with a molding pressure of 8 metric tons per square centimeter to obtain a molded body. Then the molded body was sintered at a temperature of 950 ° C. for one hour under a vacuum of 10 -3 Pa to obtain a sample of a contacts material.
  • the condition was the same as the condition for Comparative example 6, except the volume ratio of V:Ta. The ratio was adjusted by the thickness of the coating of the composite powders.
  • Vanadium powders having an average grain size of 100 micrometers were coated mechanically with tantalum powders having an average grain size of 3 micrometers to prepare composite powders.
  • the volume ratio of V:Ta was adjusted by the thickness of the coating of the composite powders.
  • the composite powders were filled in an aluminum oxide crucible and were sintered at a temperature of 1200° C. for one hour under a vacuum of 10 -3 Pa to obtain a skeleton.
  • An oxygen-free copper was infiltrated into the skeleton at a temperature of 1150° C. for 0.5 hours under a vacuum of 10 -3 Pa to obtain a sample of a contacts material.
  • Example 6 The same composite powders as in Example 6 were used.
  • the composite powders were molded by pressuring with a molding pressure of one metric tons per square centimeter to obtain a molded body. Then the molded body was sintered at a temperature of 1200° C. for one hour under a vacuum of 10 -3 Pa to obtain a skeleton.
  • An oxygen-free copper was infiltrated into the skeleton at a temperature of 1150° C. for 0.5 hours under a vacuum of 10 -3 Pa to obtain a sample of a contacts material.
  • the condition is the same as in Example 7, except that the molding pressure is 2 metric tons per square centimeter.
  • Example 8 consists in contacts of 45 Zr--5 Mo--30 Cu--15 Ag, while Example 9 consists in contacts of 30 Zr--20 Y--5 Mo--Cu; each of these were manufactured by the infiltration method, covering the surface of the arc-proof material with auxiliary constituent.
  • Zirconium powders having an average grain size of 100 micrometers were coated mechanically with molybdenum powders and niobium powders having an average grain size of 3 micrometers, respectively, to prepare composite powders.
  • the composite powders were filled in an aluminum oxide crucible and were sintered at a temperature of 1200° C. for one hour under a vacuum of 10 -3 Pa to obtain a skeleton.
  • a Cu--Ag alloy having a composition that the ratio of Cu:Ag is 2:1 was infiltrated into the skeleton at a temperature of 1000° C. for 0.5 hours under a vacuum of 10 -3 Pa to obtain a sample of a contacts material.
  • Each of these contacts was found to have a conductivity and exhibit a circuit breaking capability of the same order as or better than that of the prior art Cu--Cr contacts.
  • Cr is found to be used as one of the arc-proof constituents of this invention.
  • breaking capability can be improved not merely by the compositions of these Examples but also by employing at least one of CP, Ti, Zr, V, and Y as arc-proof material, at least one of Ta, Nb, W and Mo as auxiliary constituent, and at least one of Cu and Ag as conductive constituent.

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  • High-Tension Arc-Extinguishing Switches Without Spraying Means (AREA)
  • Contacts (AREA)
US08/181,085 1993-02-02 1994-01-13 Contacts material for vacuum valve Expired - Fee Related US5500499A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP5-015060 1993-02-02
JP5015060A JP2766441B2 (ja) 1993-02-02 1993-02-02 真空バルブ用接点材料

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US5500499A true US5500499A (en) 1996-03-19

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Country Status (7)

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US (1) US5500499A (fr)
EP (1) EP0610018B1 (fr)
JP (1) JP2766441B2 (fr)
KR (1) KR0145245B1 (fr)
CN (1) CN1045682C (fr)
DE (1) DE69417606T2 (fr)
TW (1) TW250571B (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5698008A (en) * 1994-02-21 1997-12-16 Kabushiki Kaisha Toshiba Contact material for vacuum valve and method of manufacturing the same
US6346683B1 (en) * 1999-02-02 2002-02-12 Kabushiki Kaisha Toshiba Vacuum interrupter and vacuum switch thereof
US6437275B1 (en) * 1998-11-10 2002-08-20 Hitachi, Ltd. Vacuum circuit-breaker, vacuum bulb for use therein, and electrodes thereof
US6476338B2 (en) * 2000-02-08 2002-11-05 Kabushiki Kaisha Toshiba Vacuum switch
US20050092276A1 (en) * 2003-10-29 2005-05-05 Ritter Clyde G. Durable valve lifter for combustion engines and methods of making same
US20070000763A1 (en) * 2005-07-01 2007-01-04 Minoru Karaki Movable contact assembly, method of manufacturing the same, and switch using the same
US20070034185A1 (en) * 2003-10-29 2007-02-15 Ritter Clyde G Durable valve lifter for combustion engines and methods of making same
US10361039B2 (en) * 2015-08-11 2019-07-23 Meidensha Corporation Electrode material and method for manufacturing electrode material

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08249991A (ja) * 1995-03-10 1996-09-27 Toshiba Corp 真空バルブ用接点電極
US9368301B2 (en) * 2014-01-20 2016-06-14 Eaton Corporation Vacuum interrupter with arc-resistant center shield

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0101024A2 (fr) * 1982-08-09 1984-02-22 Kabushiki Kaisha Meidensha Matériau de contact pour interrupteur à vide et son procédé de fabrication
EP0109088A1 (fr) * 1982-11-16 1984-05-23 Mitsubishi Denki Kabushiki Kaisha Matériau de contact pour interrupteurs sous vide
EP0110176A2 (fr) * 1982-11-01 1984-06-13 Mitsubishi Denki Kabushiki Kaisha Matériau de contact pour interrupteur à vide
JPS59201333A (ja) * 1983-04-28 1984-11-14 三菱電機株式会社 真空しや断器用接点材料
JPS59201331A (ja) * 1983-04-28 1984-11-14 三菱電機株式会社 真空しや断器用接点材料
JPS59201335A (ja) * 1983-04-29 1984-11-14 三菱電機株式会社 真空しや断器用接点材料
JPS59201334A (ja) * 1983-04-29 1984-11-14 三菱電機株式会社 真空しや断器用接点材料
US4743718A (en) * 1987-07-13 1988-05-10 Westinghouse Electric Corp. Electrical contacts for vacuum interrupter devices
US4830821A (en) * 1986-01-21 1989-05-16 Kabushiki Kaisha Toshiba Process of making a contact forming material for a vacuum valve

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2778826B2 (ja) * 1990-11-28 1998-07-23 株式会社東芝 真空バルブ用接点材料

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0101024A2 (fr) * 1982-08-09 1984-02-22 Kabushiki Kaisha Meidensha Matériau de contact pour interrupteur à vide et son procédé de fabrication
US4640999A (en) * 1982-08-09 1987-02-03 Kabushiki Kaisha Meidensha Contact material of vacuum interrupter and manufacturing process therefor
EP0110176A2 (fr) * 1982-11-01 1984-06-13 Mitsubishi Denki Kabushiki Kaisha Matériau de contact pour interrupteur à vide
EP0109088A1 (fr) * 1982-11-16 1984-05-23 Mitsubishi Denki Kabushiki Kaisha Matériau de contact pour interrupteurs sous vide
JPS59201333A (ja) * 1983-04-28 1984-11-14 三菱電機株式会社 真空しや断器用接点材料
JPS59201331A (ja) * 1983-04-28 1984-11-14 三菱電機株式会社 真空しや断器用接点材料
JPS59201335A (ja) * 1983-04-29 1984-11-14 三菱電機株式会社 真空しや断器用接点材料
JPS59201334A (ja) * 1983-04-29 1984-11-14 三菱電機株式会社 真空しや断器用接点材料
US4830821A (en) * 1986-01-21 1989-05-16 Kabushiki Kaisha Toshiba Process of making a contact forming material for a vacuum valve
US4743718A (en) * 1987-07-13 1988-05-10 Westinghouse Electric Corp. Electrical contacts for vacuum interrupter devices

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5698008A (en) * 1994-02-21 1997-12-16 Kabushiki Kaisha Toshiba Contact material for vacuum valve and method of manufacturing the same
US5882448A (en) * 1994-02-21 1999-03-16 Kabushiki Kaisha Toshiba Contact material for vacuum valve and method of manufacturing the same
US6437275B1 (en) * 1998-11-10 2002-08-20 Hitachi, Ltd. Vacuum circuit-breaker, vacuum bulb for use therein, and electrodes thereof
US6346683B1 (en) * 1999-02-02 2002-02-12 Kabushiki Kaisha Toshiba Vacuum interrupter and vacuum switch thereof
US6476338B2 (en) * 2000-02-08 2002-11-05 Kabushiki Kaisha Toshiba Vacuum switch
US20050092276A1 (en) * 2003-10-29 2005-05-05 Ritter Clyde G. Durable valve lifter for combustion engines and methods of making same
US7086361B2 (en) 2003-10-29 2006-08-08 Jerry Burnham Durable valve lifter for combustion engines and methods of making same
US20070034185A1 (en) * 2003-10-29 2007-02-15 Ritter Clyde G Durable valve lifter for combustion engines and methods of making same
US7530339B2 (en) 2003-10-29 2009-05-12 Jerry Burnham Of C & B Aviation Durable valve lifter for combustion engines and methods of making same
US20070000763A1 (en) * 2005-07-01 2007-01-04 Minoru Karaki Movable contact assembly, method of manufacturing the same, and switch using the same
US7161103B1 (en) * 2005-07-01 2007-01-09 Matsushita Electric Industrial Co., Ltd. Moveable contact assembly, method of manufacturing the same, and switch using the same
US10361039B2 (en) * 2015-08-11 2019-07-23 Meidensha Corporation Electrode material and method for manufacturing electrode material

Also Published As

Publication number Publication date
DE69417606D1 (de) 1999-05-12
EP0610018B1 (fr) 1999-04-07
KR0145245B1 (ko) 1998-08-17
KR940020442A (ko) 1994-09-16
TW250571B (fr) 1995-07-01
DE69417606T2 (de) 1999-12-09
CN1045682C (zh) 1999-10-13
JPH06231658A (ja) 1994-08-19
JP2766441B2 (ja) 1998-06-18
EP0610018A1 (fr) 1994-08-10
CN1112722A (zh) 1995-11-29

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